The biggest problem in robot design is power. Today, a robot would need an onboard cylinder or compressor; in either case, it would need to refill with air or electricity regularly. Shadow sees a number of ways round this problem. In one, a robot would know it must go to a recharging station and swap its battery or refill its air cylinder. When it’s working in one room (eg doing the washing-up), it may be practical to have a pipe/cable coming out of the ceiling which keeps the robot permanently charged. However, Shadow hopes that the leaps being made by fuel cell technology will supplant any worries it has in this department.
In terms of force, the air muscles used by Shadow are capable of considerable feats of strength. Nevertheless, the idea of building a super-human robot doesn’t appeal. The robot must have the ability to pick up a mug, but not to crush someone’s hand. It is therefore anticipated that its `muscles’ will produce about as much power as a human muscle does in a state of repose. Shadow’s biped, for example, derives the speed and power necessary for walking from only two atmospheres air pressure.